1. Field of the Invention
The present invention relates generally to computer-assisted design (CAD) systems, and in particular, to a graphics program that determines a distribution of spines on a curvature comb.
2. Description of the Related Art
Over the last decades, designers have changed their fundamental approach to graphics design, with the increasing power of computer-implemented graphics programs. New software makes sophisticated graphics technology available and affordable to virtually anyone.
Often, graphics programs are used to generate and display curves. The curve may be planar, but it may also be on a surface, or even twisting in space.
Curvature combs may be used to visualize the smoothness of a curve. A comb generally comprises a number of spines (also called “teeth” or “bristles”), which are line segments drawn perpendicular to the curve. Each spine has one endpoint on the curve, and the other endpoint located a distance away from the curve equal to the curvature of the curve at that point. The spine is drawn in the direction opposite the direction in which the curve is bending. Often, the spines are scaled by some function for easier visibility.
Curvature combs allow users to easily identify inflections in the curve. An inflection point is identified when the spines of the comb jump from one side of the curve to the other side of the curve.
Curvature combs also allow users to identify higher order discontinuities in the curve. Generally, an nth order discontinuity in the curve is visible as an (n−1)th order discontinuity in the curvature comb.
Notwithstanding the current usefulness of curvature combs, there is still a need for improvements.